In general, a multiprocessor, including a shared memory, performs a message notification event between processors through an inter-processor interrupt (IPI) that is an interrupt for asynchronous event notification. For example, when a processor A transfers a message to a processor B, the processor A generates the IPI to be transmitted to the processor B after storing a message that is to be transmitted on the shared memory. The processor B, in which an interrupt occurs, stops an existing execution flow and receives a message arrival event and a message, and thus a message notification is performed.